The domain of r: (3,-2) (1,2) (-1,-4) (-1,2)

domain {-1,1.3}

Step-by-step explanation:

The domain is the input values, or in this case the first or x values

domain {3,1,-1,-1}

We do not put the same value twice

domain {3,1,-1}

We like to put them in numerical order

domain {-1,1.3}